Electric drive axle light truck model motor performance and whole truck dynamic property evaluation method

Abstract

The invention relates to an electric drive axle light truck model motor performance and whole vehicle dynamic property evaluation method, which comprises the following steps: inputting whole vehicle parameters and performance requirements, selecting target vehicle model parameters, and determining a driving form; performing motor performance matching analysis, and selecting electric drive assembly parameters according to the target vehicle model parameters and the drive form; evaluation analysis: performing dynamic performance analysis on the target vehicle model parameters and the electric drive assembly parameters; testing the power performance of the whole vehicle, namely testing the selected electric drive assembly according to test items of the maximum vehicle speed, the acceleration capability and the maximum gradeability based on a sample vehicle test and a simulated loading condition to obtain test data of the test; and evaluating the power performance of the whole vehicle, calculating and analyzing the electric drive assembly under the same parameter requirement of the whole vehicle, and evaluating in combination with experimental test data to obtain a power performance evaluation result, thereby providing theoretical support for a whole vehicle scheme, realizing the power performance and cost advantages of the new energy commercial vehicle, and optimizing the development of a whole vehicle power assembly system scheme.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy commercial vehicles, and particularly relates to a method for evaluating the motor performance and the vehicle power performance of an electric drive axle light truck model. Background Art

[0002] As the main force in transportation, the green development of light trucks is an inevitable trend in the industry. It is particularly important to comprehensively explore new energy technology routes such as pure electric, hybrid, and hydrogen fuel cell. For multiple market segments such as municipal sanitation, urban construction and muck transportation, short-distance towing, and high-speed towing, different application scenarios have different technical requirements for vehicles. Among them, the pure electric technology route is relatively easy to implement and has a high maturity. Multiple drive schemes can be adopted. The direct drive scheme can quickly achieve "converting from fuel to electricity", but it has a low power density and a large volume and is in a decline period; the single-reduction scheme is used in light trucks, small trucks, and micro-truck models due to its advantages in terms of self-weight and efficiency; the motor + AMT transmission scheme can handle complex working conditions and is mainly applied to medium and heavy truck models, and some are applied to light trucks; the electric drive axle is similar to the single-reduction technology scheme, reducing the assembly mounts, drive shafts, etc., with a high integration degree, and is applied to urban working conditions with relatively good working conditions. The new energy light truck market is highly competitive, and users have strong demands in terms of cost and performance. Therefore, when developing the powertrain system, it is necessary to consider both power performance and economy. When the powertrain system adopts the electric drive axle scheme, it can reduce costs and weight while meeting the vehicle power performance, and is also beneficial to the vehicle layout. Summary of the Invention

[0003] The object of the present invention is to overcome the deficiencies of the prior art and provide a method for evaluating the motor performance and the vehicle power performance of an electric drive axle light truck model.

[0004] To solve the problems in the above background art, the present invention is realized through the following technical solutions:

[0005] A method for evaluating the motor performance and the vehicle power performance of an electric drive axle light truck model, comprising:

[0006] S1, input the vehicle parameters and performance requirements, select the target vehicle model parameters, and determine the drive form, where the drive form is rear-wheel centralized drive;

[0007] S2, perform motor performance matching analysis, and select the electric drive assembly parameters according to the target vehicle model parameters and the drive form;

[0008] S3, perform evaluation analysis, and perform power performance analysis on the target vehicle model parameters and the electric drive assembly parameters through three evaluation methods: theoretical calculation analysis, matlab simulation calculation, and cruise simulation analysis;

[0009] S4. Vehicle dynamic performance test: Based on the test of the prototype vehicle, simulate the loading conditions, and test the selected electric drive assembly in S2 according to the test items of maximum vehicle speed, acceleration ability and maximum climbing gradient to obtain the test data.

[0010] S5. Vehicle dynamic performance evaluation: Calculate and analyze the electric drive assembly with the same vehicle parameter requirements through theoretical calculation analysis, Matlab simulation calculation and Cruise simulation analysis, and combine the test data for evaluation to obtain the dynamic performance evaluation results.

[0011] Preferably, in S1, the vehicle parameters include total vehicle mass, frontal area, air resistance coefficient, rolling resistance coefficient, tire rolling radius and transmission system efficiency.

[0012] Preferably, the theoretical calculation analysis in S3 is as follows: Based on the vehicle motion state, driving force and running resistance, establish the vehicle driving equation according to the force balance relationship to calculate the maximum vehicle speed, acceleration and maximum climbing gradient of the vehicle.

[0013] Combined with the vehicle parameters, analyze the vehicle performance requirements. According to the vehicle dynamics characteristics, during the vehicle driving process, the resistance suffered includes air resistance, rolling resistance, acceleration resistance and gradient resistance, and the relationship between its driving force and resistance is expressed as:

[0014] F(t) = F f (t) + F i (t) + F w (t) + F j (t)

[0015] Where: F f (t) is the rolling resistance, F i (t) is the gradient resistance, F w (t) is the air resistance, F j (t) is the acceleration resistance, and F(t) is the driving force generated by the vehicle.

[0016] The power requirement at the maximum vehicle speed is:

[0017]

[0018] Where:

[0019] P v_max is the rated power of the drive motor, m is the total vehicle mass, V max is the maximum vehicle speed, g is the acceleration due to gravity, f is the rolling resistance coefficient, C D is the air resistance coefficient, A is the frontal projected area of the vehicle, η t is the mechanical efficiency of the transmission system, i g is the gear ratio of the highest gear of the transmission, i ois the drive axle speed ratio, r is the tire rolling radius;

[0020] The power requirement of the vehicle at the maximum climbing grade is:

[0021]

[0022] The torque requirement of the vehicle at the maximum climbing grade is:

[0023]

[0024] Where:

[0025] P i_max is the power required for driving the motor to climb, T max is the required torque for climbing, V i is the climbing speed, α max =tan -1 (i max ), where i max is the road slope, α max is the climbing angle;

[0026] The power of the vehicle at the shortest acceleration is:

[0027]

[0028] Where: P j_max is the power required for the drive motor to accelerate, δ is the conversion factor for the vehicle's rotating mass, and V is the vehicle speed at the end of acceleration.

[0029] Preferably, in S3, the MATLAB simulation calculation is to establish a mathematical operation model based on the theoretical calculation formula, write a simulation program, input the parameters of the whole vehicle and the electric drive assembly, run the simulation program, and output the analysis results and curve data.

[0030] Preferably, in S3, the cruise simulation analysis is:

[0031] Modular system components are used to build a vehicle parameter model, which includes a vehicle module, a driver module, a tire module, a main reducer module, a motor module, and a battery module. Corresponding parameters are set for each module, and the simulation task is established using the working conditions of the vehicle parameter model, and finally the simulation analysis results are output.

[0032] Compared with the prior art, the present invention has the following beneficial technical effects:

[0033] Through theoretical calculation analysis, Matlab simulation calculation, and the application of Cruise simulation analysis, a step-by-step and in-depth evaluation analysis from the outside to the inside can objectively and comprehensively compare and analyze the motor performance and vehicle dynamic performance, providing theoretical support for the vehicle plan, achieving the dynamic performance and cost advantages of new energy commercial vehicles, and optimizing the development of the vehicle powertrain system plan. Description of the Drawings

[0034] Figure 1 This is the flowchart of the present invention. Detailed Implementation Manner

[0035] As Figure 1 shown, a method for evaluating the motor performance and vehicle dynamic performance of an electric drive axle light truck model includes:

[0036] S1. Input the vehicle parameters and performance requirements, select the target vehicle model parameters, and determine the drive form, where the drive form is rear-wheel centralized drive;

[0037] S2. Conduct motor performance matching analysis, and select the electric drive assembly parameters according to the target vehicle model parameters and drive form;

[0038] S3. Conduct evaluation analysis, and perform dynamic performance analysis on the target vehicle model parameters and electric drive assembly parameters through three evaluation methods: theoretical calculation analysis, Matlab simulation calculation, and Cruise simulation analysis;

[0039] S4. Conduct vehicle dynamic performance testing. Based on the prototype vehicle test, simulate the loading conditions, and test the electric drive assembly selected in S2 according to the test items of the maximum vehicle speed, acceleration ability, and maximum climbing gradient to obtain the test data;

[0040] S5. Conduct vehicle dynamic performance evaluation. Calculate and analyze the electric drive assembly under the same vehicle parameter requirements through theoretical calculation analysis, Matlab simulation calculation, and Cruise simulation analysis, and combine the test data for evaluation to obtain the dynamic performance evaluation results.

[0041] In S1, the vehicle parameters include the total vehicle mass, frontal area, air resistance coefficient, rolling resistance coefficient, tire rolling radius, and transmission system efficiency.

[0042] In S3, the theoretical calculation analysis is as follows: Based on the vehicle motion condition, the driving force and running resistance, establish an automobile driving equation according to the force balance relationship to calculate the maximum vehicle speed, acceleration, and maximum climbing gradient of the vehicle;

[0043] Combined with the vehicle parameters, analyze the vehicle performance requirements. According to the vehicle dynamics characteristics, during the driving process of the vehicle, the resistances it receives include air resistance, rolling resistance, acceleration resistance, and gradient resistance. The relationship between its driving force and resistance is expressed as:

[0044] F(t) = F f (t) + F i (t) + F w (t) + F j (t)

[0045] Where: F f (t) is the rolling resistance, F i (t) is the grade resistance, F w (t) is the air resistance, F j (t) is the acceleration resistance, and F(t) is the driving force generated by the vehicle;

[0046] The power demand at the maximum vehicle speed is:

[0047]

[0048] Where:

[0049] P v_max is the rated power of the drive motor, m is the total vehicle mass, V max is the maximum vehicle speed, g is the acceleration due to gravity, f is the rolling resistance coefficient, C D is the air resistance coefficient, A is the frontal projected area of the vehicle, η t is the mechanical efficiency of the transmission system, i g is the gear ratio of the highest gear of the transmission, i o is the final drive ratio, and r is the rolling radius of the tire;

[0050] The power demand at the maximum gradeability of the vehicle is:

[0051]

[0052] The torque demand at the maximum gradeability of the vehicle is:

[0053]

[0054] Where:

[0055] P i_max is the power demand of the drive motor for climbing, T max is the torque demand for climbing, V i is the climbing vehicle speed, α max = tan -1 (i max ), where i max is the road surface gradient, and α max is the climbing angle;

[0056] The power during the shortest acceleration of the vehicle is:

[0057]

[0058] Where: P j_max is the power required for the drive motor to accelerate, δ is the conversion factor for the vehicle's rotating mass, and V is the vehicle speed at the end of acceleration.

[0059] In S3, the MATLAB simulation calculation is to establish a mathematical operation model based on the theoretical calculation formula, write a simulation program, input the parameters of the whole vehicle and the electric drive assembly, run the simulation program, and output the analysis results and curve data.

[0060] In S3, the cruise simulation analysis is:

[0061] Modular system components are used to build a vehicle parameter model, which includes a vehicle module, a driver module, a tire module, a main reducer module, a motor module, and a battery module. Corresponding parameters are set for each module, and the simulation task is established using the working conditions of the vehicle parameter model, and finally the simulation analysis results are output.

[0062] Example 2

[0063] A method for evaluating the motor performance and vehicle dynamics of an electric drive axle light truck.

[0064] S1, input vehicle parameters and performance requirements, select target vehicle model parameters, and determine the drive form, which is rear-wheel drive centralized drive; the target vehicle model parameters are shown in Table 1:

[0065]

[0066]

[0067] Table 1

[0068] S2, motor performance matching analysis, select the electric drive assembly parameters according to the target vehicle model parameters and drive form; the electric drive assembly parameters are shown in Table 2:

[0069]

[0070] Table 2

[0071] S3, evaluation and analysis, through theoretical calculation analysis, MATLAB simulation calculation, cruise simulation analysis three evaluation methods to analyze the target vehicle model parameters and electric drive assembly parameters power performance

[0072] The power requirement of the vehicle at maximum speed is:

[0073]

[0074] According to the above formula, we can know the power required for the vehicle when it is fully loaded and has a maximum speed of 90km / h.

[0075] To ensure that the vehicle speed is not less than 10 km / h when the vehicle climbs the maximum gradient, the power requirement under the maximum gradient of the vehicle is as follows:

[0076]

[0077] According to the above formula, it can be calculated that the vehicle speed v i is 10 km / h under the condition of a 20% gradient, and the torque required by the whole vehicle.

[0078] The power during the shortest acceleration of the vehicle is:

[0079]

[0080] According to the above formula, it can be calculated that when the acceleration time of this vehicle model is ≤ 10 s (0 - 50 km / h) under full load, the power requirement of the motor.

[0081] The theoretical calculation results are shown in Table 3 as follows:

[0082]

[0083] Table 3

[0084] The Matlab simulation calculation is to establish a mathematical operation model based on the theoretical calculation formula, write a simulation program, input the parameters of the vehicle and the electric drive assembly, run the simulation program, and output the analysis results and curve data. The results are as follows:

[0085] The maximum vehicle speed V max = 132.40 km / h;

[0086] The acceleration time for 50 km is t = 6.50 s;

[0087] The maximum gradient angle = 25.32%.

[0088] Using modular system components, a vehicle parameter model is built. The vehicle parameter model includes a vehicle module, a driver module, a tire module, a main reducer module, a motor module, and a battery module. Corresponding parameter settings are made for each module, and a simulation task is established using the working conditions provided by the vehicle parameter model. Finally, the simulation analysis results are shown in Table 4 as follows:

[0089]

[0090] Table 4

[0091] S4. Vehicle power performance test. Based on the test of the prototype vehicle, simulating the loading conditions, with the total vehicle mass of 6t, the selected electric drive assembly in S2 is tested according to the test items of maximum speed, acceleration ability and maximum climbing gradient, and the test data are obtained. The results are shown in Table 5 as follows:

[0092]

[0093] Table 5

[0094] S5. Vehicle power performance evaluation. For the electric drive assemblies with the same vehicle parameter requirements, calculations and analyses are carried out through theoretical calculation analysis, matlab simulation calculation and cruise simulation analysis, and evaluations are made in combination with the test data to obtain the power performance evaluation results:

[0095] The power performance evaluation results are shown in Table 6 as follows:

[0096]

[0097] Table 6

[0098] Maximum speed performance: All meet the design index requirements;

[0099] Acceleration performance: All meet the design index requirements;

[0100] Maximum climbing performance: All meet the design index requirements.

Claims

1. An evaluation method for the motor performance and vehicle dynamic performance of an electric drive bridge light truck model, characterized in that, include: S1, input vehicle parameters and performance requirements, select target vehicle model parameters, and determine the drive mode, which is a rear-wheel drive centralized drive; S2, motor performance matching analysis, select electric drive assembly parameters according to target vehicle model parameters and drive form; S3, evaluation and analysis, the power performance analysis of the target vehicle model parameters and electric drive assembly parameters is carried out through three evaluation methods: theoretical calculation analysis, MATLAB simulation calculation, and cruise simulation analysis; S4, vehicle power performance test, based on the prototype test, simulates the loading condition, tests the electric drive assembly selected in S2 according to the maximum vehicle speed, acceleration capability and maximum climbing grade test items, and obtains test data; S5, vehicle power performance evaluation, the electric drive assembly under the same vehicle parameter requirements is calculated and analyzed through theoretical calculation analysis, MATLAB simulation calculation, and cruise simulation analysis, and evaluated in combination with experimental test data to obtain the power performance evaluation results.

2. The method for evaluating the motor performance and vehicle dynamic performance of an electric drive bridge light truck model according to claim 1, wherein In S1, the vehicle parameters include the total vehicle mass, frontal area, air resistance coefficient, rolling resistance coefficient, tire rolling radius and transmission system efficiency.

3. The method for evaluating the motor performance and vehicle dynamic performance of an electric drive bridge light truck model according to claim 1, wherein The theoretical calculation and analysis in S3 is as follows: through the vehicle's motion conditions, driving force and driving resistance, the vehicle's driving equation is established according to the balance relationship of forces, and the maximum speed, acceleration and maximum climbing grade of the vehicle are calculated; Combined with the vehicle parameters, the performance requirements of the vehicle are analyzed. According to the vehicle dynamics characteristics, the resistance encountered by the vehicle during driving includes air resistance, rolling resistance, acceleration resistance and slope resistance. The relationship between driving force and resistance is expressed as: F(t) = F f (t) + F i (t) + F w (t) + F j (t) Where: F f (t) is the rolling resistance, F i (t) is the gradient resistance, F w (t) is the air resistance, F j (t) is the acceleration resistance, and F(t) is the driving force generated by the vehicle; The power requirement of the vehicle at maximum speed is: Where: P v_max is the rated power of the drive motor, m is the total mass of the vehicle, V max is the maximum speed, g is the acceleration due to gravity, f is the rolling resistance coefficient, C D is the air resistance coefficient, A is the frontal projected area of the vehicle, η t is the mechanical efficiency of the transmission system, i g is the speed ratio of the highest gear of the transmission, i o is the speed ratio of the drive axle, r is the rolling radius of the tire; The power requirement of the vehicle at the maximum climbing grade is: The torque requirement of the vehicle at the maximum climbing grade is: Where: P i_max is the required power for the driving motor to climb the slope, T max is the required torque for climbing the slope, V i is the climbing vehicle speed, α max = tan -1 (i max ), where i max is the road surface gradient, α max is the climbing angle; The power of the vehicle at the shortest acceleration is: Where: P j_max is the required power for the driving motor to accelerate, δ is the conversion coefficient of the rotating mass of the vehicle, and V is the vehicle speed at the end of acceleration.

4. The method for evaluating the motor performance and the vehicle power performance of the electric drive axle light truck model according to claim 1, wherein, In S3, the MATLAB simulation calculation is to establish a mathematical operation model based on the theoretical calculation formula, write a simulation program, input the parameters of the whole vehicle and the electric drive assembly, run the simulation program, and output the analysis results and curve data.

5. The evaluation method for the motor performance and vehicle dynamic performance of the electric drive bridge light truck model according to claim 1, characterized in that, In S3, the cruise simulation analysis is: Modular system components are used to build a vehicle parameter model, which includes a vehicle module, a driver module, a tire module, a main reducer module, a motor module, and a battery module. Corresponding parameters are set for each module, and the simulation task is established using the working conditions of the vehicle parameter model, and finally the simulation analysis results are output.

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